From the Planet Waves website:
Redefining the meaning of the entry level cable, the Classic Series Microphone Cables feature heavy gauged oxygen-free copper conductors and nickel-plated brass connectors for reliable and transparent signal transfer. The signal is then protected by a layer of conductive PVC as well as a dense copper for optimal shielding coverage that protects the signal from outside interferences. To finish it off, each plug features a molded collar for outstanding strain relief, ensuring that your cable lasts. Entry level no longer means ordinary.